Creed promulgated
The Creed of this Council
Following the holy fathers, we all with one voice confess our Lord Jesus Christ to be one and the same Son, the same perfect in Godhead, the same perfect in manhood, truly God and truly man, the same of a rational soul and body; co-essential with the Father in Godhead, and the same co-essential with us in manhood... acknowledged in two natures without confusion, without change, without division, without separation; the difference of the natures being in no way removed by the union, but rather the properties of each nature being preserved, and combining in one Person and hypostasis.
Definition · No. 1
The Council's Answer
Claim refuted: "“After the Incarnation, Christ has only one nature — the divine. The human nature was absorbed. Two natures before; one after.”" — If the human nature is absorbed into the divine, Christ is not truly human — he only appears human. His suffering, death, and resurrection do not affect a human nature identical to ours. The Incarnation does not heal human nature from within, because there is no genuine human nature present. The logic of theosis — what happened to Christ's nature can happen to ours — collapses entirely.
Creed · No. 2
The Chalcedonian Definition, 451 AD
Following the holy fathers, we all with one voice confess our Lord Jesus Christ to be one and the same Son, the same perfect in Godhead, the same perfect in manhood, truly God and truly man, the same of a rational soul and body; co-essential with the Father in Godhead, and the same co-essential with us in manhood... acknowledged in two natures without confusion, without change, without division, without separation; the difference of the natures being in no way removed by the union, but rather the properties of each nature being preserved, and combining in one Person and hypostasis. — Council of Chalcedon, Definition of the Faith, 451 AD — ratified by 520 bishops
Anathema · No. 3
Against Eutychianism
“After the Incarnation, Christ has only one nature — the divine. The human nature was absorbed. Two natures before; one after.”
Anathema · No. 4
Against Eutychianism / Monophysitism
“After the Incarnation, Christ has only one nature — the divine. The human nature was absorbed. Two natures before; one after.”
Definition · No. 5
Witness — Pope St. Leo the Great (The Western Contribution)
"For each form performs the functions common to them in communion with the other — namely, the Word performing what belongs to the Word, and the flesh carrying out what belongs to the flesh. The one of them glitters with miracles, the other succumbs to insults. The one is equal to the Father in majesty, the other is inferior to the Father in humanity. As the Son of man he came down from heaven, and as the Son of God he did not leave heaven." — Pope Leo I, Tome to Flavian (Epistle 28), 449 AD. When the Tome was read at Chalcedon, the bishops reportedly declared: “Peter has spoken through Leo.” Leo's theological contribution was genuine; the Orthodox Church honors him as a Father and a saint. The ecclesiological implications of the acclamation are a matter of ongoing Orthodox-Catholic discussion.
Definition · No. 6
Witness — Eutyches of Constantinople (The Condemned)
"Before the union there were two natures; but after the union and the incarnation I confess only one. Our Lord, though born of the Holy Spirit and of the Virgin Mary, was incarnate. And if he is one with us according to the flesh, I grant him to be of the same substance with us; but the flesh of our Lord I call divine flesh. I should not say, however, that it is of the same substance as ours." — Eutyches, testimony at the Synod of Constantinople, 448 AD. The problem Chalcedon diagnosed: if the flesh of Christ is not of the same substance as ours, then what was assumed is not human nature as we have it — but something elevated, intermediate, or divine. What is not assumed cannot be healed. The council insisted on the full identity of Christ's humanity with ours.
Definition · No. 7
Witness — St. Flavian of Constantinople (Martyr of the Robber Council)
"Confessing our Lord Jesus Christ to be perfect God and perfect Man, of a reasonable soul and body, I confess him to be before the ages from the Father as to his divinity, and in the last days, for us and our salvation, born of the Virgin Mary as to his humanity; consubstantial with the Father as to his Godhead, and consubstantial with us as to his manhood." — St. Flavian, Confession of Faith presented to Emperor Theodosius II, 449 AD. Flavian's statement is essentially the Chalcedonian Definition before Chalcedon. He was beaten to death by partisans of Eutyches at the very council convened to exonerate Eutyches. Chalcedon vindicated his theology and his person.